The present invention relates to a vehicle having an internal combustion engine, and in particular to a flexible drive of the engine.
Vehicles having a longitudinally installed internal combustion engine, i.e. having an internal combustion engine, the crankshaft of which extends in a longitudinal direction of the vehicle, have a flexible drive, normally designed as a belt drive, in front of the internal combustion engine. The belt drive is driven by a belt pulley which, in turn, is driven by the crankshaft of the internal combustion engine.
For reasons of design, there is an effort to keep the “overhang” of the vehicle front structure, i.e. the distance between the front wheels and the forwardmost point of the vehicle, as short as possible. In this design requirement, there is a certain conflict of aims with the “crumple zone” required from the point of view of design for collisions, which should be as long as possible. In a head-on or frontal collision in which the front structure is compressed, the belt pulley generally becomes a single block with the engine block of the internal combustion engine.
It is the object of the invention to provide a vehicle, having an internal combustion engine and a flexible drive, which has a sufficiently large crumple zone, even in the case of a relatively short overhang.
The starting point of the invention is a vehicle having an internal combustion engine, which is installed in the vehicle in such a way that a crankshaft of the internal combustion engine extends in a longitudinal direction of the vehicle.
The internal combustion engine has a flexible drive, which has a (driving) wheel, in particular a belt pulley, which is arranged in such a way as to rotate about a longitudinal axis of the vehicle. The wheel or belt pulley is arranged in front of the internal combustion engine when viewed in the direction of travel of the vehicle. A flexible drive of this kind is used to drive auxiliary units of the internal combustion engine, e.g. a generator or a mechanically driven refrigerant compressor.
The wheel of the flexible drive has at least one “weakened section”, which is provided for the purpose of facilitating compression of the wheel (or belt pulley) in a collision, the wheel or belt pulley thus forming a part of the “crumple zone” of the front structure.
The at least one weakened section is thus used to ensure that, in a head-on collision of the vehicle, compression of the wheel in the longitudinal direction of the vehicle is allowed or facilitated. In contrast to conventional belt pulleys, which act as a virtually incompressible or hardly compressible “block” in a collision, the wheel according to the invention can be compressed at least by a few millimeters or a few centimeters, thereby extending the crumple zone of the vehicle front structure accordingly.
The wheel of the flexible drive can be produced by laser sintering, for example. That is to say, it can be a laser-sintered component. As regards their geometry, laser-sintered components can have a design of almost any degree of complexity and can be provided with recesses, undercuts or the like. Laser-sintered components offer many different ways of producing weakened sections. However, the wheel does not necessarily have to be a laser-sintered part. It can also be a casting or a turned component.
For example, weakened sections spaced apart in the circumferential direction can be provided in the wheel. The weakened sections can be designed as slots, for example. The slots can take the form of rectangles, for example. At the same time, provision can be made for the length of the slots in the longitudinal direction of the vehicle to be greater than the slot width in the circumferential direction of the wheel.
According to a development of the invention, the wheel is secured on a flywheel of the internal combustion engine. The wheel can be screwed to the flywheel, for example.
Moreover, provision can be made for the flywheel to have a groove-type depression, which can take the form of a full circle, for example. By means of a groove-type depression, a further crumple zone of several millimeters can be kept in reserve. In a head-on collision, the front side of the wheel circumference can be deflected into the groove or be deformed into the groove.
As an alternative or in addition, a “splitting element” can be provided. A “splitting element” is taken to be an element which splits the circumference of the wheel in the longitudinal direction of the vehicle at at least one point or at several points in a head-on collision of the vehicle.
In a side view of the belt pulley, the splitting element can be of “mushroom-like” design. A “shank portion” of the splitting element can be arranged concentrically with respect to the axis of rotation of the wheel. The splitting element furthermore has a “head portion”. At least one cutting-edge-type element, which penetrates into the circumferential segment of the wheel and splits the latter in a head-on collision, can be provided on an underside of the head portion of the splitting element, said underside facing the wheel. A plurality of such cutting-edge-type elements distributed in the circumferential direction can preferably be provided. For example, four cutting-edge-type elements, each spaced apart by 90° in the circumferential direction, can be provided.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.